On measurement and modelling of 2D magnetization and magnetostriction of SiFe sheets

by Lundgren, Anders

Abstract (Summary)

The development and technological aspects of a 2D magnetization and magnetostriction
measurement setup are documented and described. Local magnetic intensity
and ux density are measured with Rogowski and material encircling coils.
In-plane strain is measured with a homodyne laser interferometer. Measured and
processed time-domain signals, hysteresis plots and signature data such as loss are
presented by an e cient and communicative interface. Measurements on quadratic
silicon iron sheet samples are included. Material types tested on the setup are with
non-oriented and oriented textures. Possible excitations include uniaxial alternating
magnetic eld in the rolling and transverse directions between 10 and 300 Hz at
least. Rotational excitations are possible at least for the non-oriented and conventional
grain-oriented types. The value of the setup lies in the possibility of using it
for routine measurements on samples.
The interplay between mathematical modelling and physical experimenting is described.
Investigations by algebraic and numerical methods are done to nd a possible
way to parameterize material behaviour and include this behaviour in nite
element programs. On the basis of a proposed one-dimensional nonlinear model,
algorithms are devised to compute magnetostrictive responses to uniaxially alternating
magnetic elds. An experimental FEM program to calculate strain elds
from inhomogeneous magnetization is developed. Its use for investigation of sample
behaviour during the operation of the setup is shown. The value of the proposed
modelling methodology lies in the study of possibilities of lowering the production
of magnetostrictive vibration in transformer, motor and generator cores.
IEEE index terms: Magnetostriction, silicon steel, magnetic cores, strain, interferometry,
magnetic anisotropy, magnetic elds, magnetic measurements, magnetoelasticity,
nonlinear magnetics, power transformers, power distribution acoustic
noise, nite element methods.
TRITA-EEA-9901
ISSN 1100-1593